【摘要】 以祁连山国家公园为研究区,基于30 m分辨率数字高程模型数据,利用Arc Hydro Tools水文数据模型与河网密度法,在确定最佳集水面积阈值的基础上提取河网并划分小流域,统计小流域的部分特征参数.结果表明,集水面积阈值与河网密度呈幂函数关系,祁连山国家公园最佳集水面积阈值为6 000栅格数;河网提取结果与全国1:250 000三级水系流域数据集的河网套合差为2.62%,叠加至遥感图像对比,发现提取结果相较于全国1:250 000三级水系流域数据集更接近真实水系;共划分祁连山国家公园小流域5 717个,约80%的小流域面积在3～50 km~2.从提取效率和结果精度来看, Arc Hydro Tools模型与河网密度法相结合可较准确提取山地区域河网及小流域.更多还原

【Abstract】 Taking the Qilian Mountains National Park(QLP) as the study area and based on DEM data with 30 m resolution, the hydrological data model of Arc Hydro Tools and the river network density method were used to extract the river network and divide the small watershed after a determination of the optimal catchment area threshold, and some characteristic parameters of the small watershed were computed.The results showed that the catchment area threshold was a power function of river network density, and the optimal catchment area threshold in QLP was 6 000 grids. The river network matching difference between the extraction results and the national 1∶250 000 tertiary river basin data set was 2.62%. Superimposed to remote sensing images, it was found that the extracted results were closer to the real water system than the national 1∶250 000 tertiary river basin data set. There were 5 717 small basins in QLP,about 80% of which covered an area of 3-50 km~2. From the perspective of extraction efficiency and result accuracy, the combination of the Arc Hydro Tools model and river network density method could accurately extract river network and small watershed in mountainous region.更多还原